At the Okinawa Institute of Science and Technology in Japan, neurobiologist Kenji Doya is ankle-deep in rodents. Not real ones, but "cyber rodents" made of plastic and silicon. Two of the critters circle each other in a mating dance. Others forage for fresh batteries on the floor. Another one just sits there. "That one is lazy," says Doya, who also heads a group at the Advanced Telecommunications Research Institute in Kyoto. "It doesn't expend energy to get a reward" -- and probably won't last long.

Groups of robots have been fixtures in academic robotics labs for years. But Doya's project is one of the first to use robots to probe how administering rewards to individuals when they achieve simple goals can give rise to intelligent group behaviors. This work could help designers build machines that collaborate to carry out complex tasks. By studying how groups of mobile robots interact and adapt, researchers could eventually develop self-sufficient swarms of robots that explore hostile environments, gather surveillance data, and repair equipment remotely.